2.1. Introduction
The recent and substantial decrease in cost of microelectronics related to sensing, flight control, and networking have facilitated the design of disposable, low cost UAVs for single-mission applications. Existing designs for folding-wing-locking mechanisms and canister-based launchers involve the use of heavy, expensive hardware such as latches, springs and hydraulic actuators. These mechanisms allow for reversibility and reliability over hundreds of cycles but they are very heavy and expensive.
US Pat. Appn. Pub. No. 2008/0149758 (Colgren et al.) discloses a modular UAV with two or four detachable wing sections that may be assembled on site to construct the functional UAV. On site assembly prior has many shortcomings such as requiring time and exposure in a potentially hazardous launch area.
U.S. Pat. No. 8,146,855 (Ismailov et al.) discloses a jet engine launched UAV with a tripartite hinged wing and a deployment mechanism at each hinge point designed to be reloaded into a pod for subsequent use. The hinged wings are designed to be reversibly opened and closed.
US Pat. Appn. Pub. No. 2009/0206196 (Parks et al.) discloses a very high altitude aircraft with a foldable wing with inflatable ribs and rigid hinged elements. The wing elements may be reversibly inflated for use or deflated for storage and require continuous gas pressure to maintain the flight configuration.